Tunnel-form.



G. D. -MOARTHUR.

TUNNEL FORM. APPLICATION FILED $211.4, 1910.

@m WM v w 2 0 V u WM V as 82 WET ESSES c. D. MGA'RTHUR.

TUNNEL FORM.

APPLICATION FILED MBA, 1910.

Patented Nov 28, 1911.

2SHEBTS-SHBET 2.

WITNESSES! w shaft 26 detachably engaging at its upper forked end the-bolt 27 upon which the gusset plates 3 and 4 are pivoted. The shaft 26 is detachably connected at 28 with the shaft section 29, and this latter section 29 is raised and lowered by means ofthe jack screw 30 mounted in the base 31. By this means provision is made for raising and lowering the arched portion of the form. The standard 0 is merely seated upon the plat-form 13, and is held releasably thereupon by means of the turn buckles 32, which turn-buckles are detachablysecured at their lower ends to the platform 13 by means of'the pins 33. The guide member 25 carries another pair of turn-buckles 34 having their outer ends in detachable engagement with the gusset plates 35 carried by the sections 1 and 2. The releasable engagement between the outer ends of the turnbuckle rods and the plates is secured by means of the pins 36.

In operation the truck carrying the ribs or channels A, B and C is brought to the desired position in the excavation, and the turn-buckles 15, 16 and 34 and the jack 3O are operated to position the ribs exactly as desired. The bottom'lagg-ing plates D are then secured in position upon the channels, and the standards 0 with their turnbuckles 34 and shaft 26 are then all removed from the platform 13, and concrete is brought along the platform 13 and supplied behind the lagging plates D until it,

reaches the top of the plates. The next lagging plates E are then positioned and the concrete filled in behind these plates. The operation is continued with the plates F, G, H, I, K, L and M until the lagging plates are all in position and the entire space between the inner surface of the excavation and the outer surface of the lagging filled with concrete. The standards 0 may then be placed in position, and the turn-buckles 32 & 34, and the shaft 26 positioned, it being understood that the necessary bulk-heads are provided at the desired points along the outer surface of the lagging toprevent the concrete from fiowin'g out endwise. After the concrete has set, the,plates 8 and 9 are detached from the sections 1 and 2, and such sections 1 and 2 collapsed by means of the turn-buckles 34 and the jack screw 30. The turn-buckles l5 and 16 are then operated to collapse-the side sections 6 and Tand the truck carrying the ribs and lagging may bemoved forward to a new position, at which point the lagging is-removed and the ribs expanded to their outer positions and secured together by means of the plates 8 and 9. The standards O are then removed again, and the operation as heretofore described repeated. It will be seen from the foregoing that the mold may be very easily and conveniently handled, and that'by means of the removable standards 0 plenty of room is given for handling the concrete'without interference. The arrangement also provides for the freeing of the lagging from the concrete without difficulty, and for the transportation of the lagging plates to their new location. The engaging means between the plates 17 and 22 provide for a positive support of the side members 6 and 7, and serve to steady the entire apparatus and maintain it in proper position. Other advantages incident to the construction will be apparent to those skilled in the art.

Having thus described my invention and illustratedits'use, what I claim as new and desire to secure by Letters Patent is the following 1. In combination in a tunnel form open at the bottom, a series of supporting ribs, lagging plates detachably secured to the ribs one above the other, a truck movable lon gitudinallyof the form, collapsing means for the lower portions of the ribs carried by the truck, a working platform comprising the upper portion of the truck, and removable collapsing and lowering means for the upper portions of the ribs carried by the truck above the platform.

2. In combination in a tunnel form open at the bottom, a series of continuous collapsible supporting ribs each comprising an upper arch portion, and a lower side portion at each end thereof, lagging plates detachably secured to the ribs one above the other, a truck movable longitudinally of the form, collapsing means for the side portions of the ribs, a working platform comprising the upper portion of the truck, and removable collapsing and supporting means for the arch portions of the ribs carried by the truck above the platform. 7

3. In combination in a tunnel form open at the bottom, a series of supporting ribs each comprising an upper arch portion in two sections hinged together at substantially the center of the mold and alower side portion at the lower end of each section thereof, lagging plates detachably secured to the ribs one above the other, a truck movable longitudinally of the form, collapsing means for the side portions of the ribs, a working platform comprising the upper portion of the truck, and removable collapsing and supporting means for the arch portions of the ribs carried by the truck above the plat form.

4. In combination in a tunnel form open at the bottom, a series of supporting ribs each comprising an upper arch portion in two sections hinged together and a lower side portion detachably secured'to the lower end of each section thereof, lagging plates detachably secured to the ribs one above the other, a truck body movable longitudinally of the form, collapsing means for the side Looasee portions of the ribs, an elevated Working platform mounted upon upright supports carried by the truck body, and a standard removably mounted upon the platform and provided with an elevating bar and laterally extending collapsing rods detachably secured to the ribs.

In combination in a tunnel form open at the bottom, a series of continuous collapsible supporting ribs, each comprising an arch portion and side sections, lagging plates detachably secured to the ribs one above the other, a truck movable longitudinally of the form, collapsing means for the side sections out the ribs, a Working platform comprising the upper portion of the truck, and removable raising and lowering means for the ribs carried by the truck above the platform.

6. In combination in a tunnel form open at the bottom, comprising a series of supporting ribs each comprising an upper arch portion in two sections hinged together at substantially the center of the mold and a loiver side section detachably secured to the lower end of cach section thereof, lagging plates detachably secured to the ribs one above the other, a truck movable longitudinally of the form, collapsing means for the side sections of the ribs, a working platform comprising the upper portion of the truck, and removable raising and lowering means for the ribs carried by the truck above the platform.

In testimony whereof I have hereunto signed my name in the presence of the two subscribed 'Wii'HESSQS.

CHARLES D. liloARlTHUll.

Witnesses HARVEY L. Lnormnn,

JOHN V. WHITE. 

